The present invention relates to a camera system, having a camera that can record an image of an object to be photographed using a CCD (Charge Coupled Device) and a display device for displaying the photographed image.
Recently, digital cameras which electronically store data related to a photographed image have become popular. The digital camera converts an optical image to electronic image data and digitally records the image data on a recording medium, such as an IC card. When the image is reproduced, the recorded digital data is retrieved from the storage medium and displayed on a display device or printed out as a hard copy image.
Generally, a CCD receives the optical image and outputs an electrical signal corresponding to the optical image. The electrical signal is A/D converted, and then stored on a recording medium, such as a floppy disk or an IC memory card. The CCD is constructed such that photoelectric elements, such as photodiodes which convert the intensity of light into an electric charge, are arranged in a matrix. The electric charge generated in each element is transferred in vertical and horizontal directions. Thus, the image data for one picture frame, which is obtained by exposing the CCD to an object image, is outputted as a series of data and transferred by horizontal and vertical CCD shift registers HCCD and VCCD, respectively, and recorded onto the recording medium.
In this type of camera, since the size of the image data outputted by the CCD is large, if the image data is recorded as is, the recording medium can store only a small number of pictures. Therefore, the image data obtained by the CCD is compressed before it is recorded. When reproducing the image, the compressed data is read out and expanded.
If the camera uses the above described system, since the compression takes a certain period of time, the data outputted by the CCD should first be stored unmodified, in a data storage memory (a field memory or a frame memory). Then, the stored data is compressed. With this construction, a large capacity data storage memory is required, since a large amount of data must be compressed. However, a large capacity memory is physically large, resulting in the overall size of the camera being large. Further, a large capacity memory is expensive, thereby increasing the cost of manufacturing the camera.
Further, in this type of camera, it is desirable that the camera display the picture immediately after photographing the object. In order to display the photographed image, the image data is stored in an image memory, and then, the stored image data is used to drive a display device. However, in this system, the image memory is used only for storing the image data that is used for driving the display device. Therefore, in order to store data on a recording medium, as well as display data on a display device, the camera must be provided with a data storage memory and an image memory. However, both memories are large capacity memories and are therefore physically large and expensive, thereby increasing the size of the camera and its manufacturing cost.